Hydraulically operated vertically storing dock levelers typically are mounted on hinges several feet behind the doorway of a loading dock. They are stored vertically to allow the loading dock door to seal directly to the pit floor. This provides better security for the loading dock, cleanliness and energy conservation when compared with conventional pit levelers. The control systems used to actuate these hydraulic devices usually have safeguards to protect workers from injury due to the potential energy stored in the raised leveler. However, there still may be an opportunity for someone to lower the leveler while another person is standing between the raised leveler and the door, because the raised leveler may block the view of the operator. In some installations, a special switch or "Emergency Stop Button" has been mounted on the under side of the leveler to allow someone to stop the lowering of the leveler. A limitation of the "Emergency Stop Button" is that the person may panic and miss the button. Also, a person needs to understand that the button is even present to stop operations.